online combinations of sample preparation and chromatographic techniques

... toxic chemicals and enhance productivity of data are needed [6,7] 1.2 Sample preparation techniques Well-established methods of sample preparation, which have been used as standard methods by ... the use of microlitres of organic solvent for the extraction and enrichment of analytes This work focuses on the development and application of two kinds of liquidphase microextraction techniques ... concentration of i in the donor phase (sample) , Va1 is the volume of donor solution (sample) , Vo is the volume of organic solvent in the pores of the hollow fiber, and Va2 is the volume of acceptor...

Ngày tải lên: 17/09/2015, 17:20

... various pH and irradiation sources (sunlight, darkness, indoor incandescent lighting and artificial UV lighting) Hydrolysis was found to be very much 143 pH-dependent irrespective of the type of water ... applied to analyze the residues of N-methylcarbamate and related compounds (propoxur and its metabolisms as model compounds) in biological materials (goldfish, tortoises and sea lettuce) Orthogonal ... recoveries of tested compounds in goldfish, tortoises and algal samples under the respective optimum MAE conditions ranged from 85% to 87% with good reproducibility The conjugate of 2-isopropoxyphenol...

Ngày tải lên: 16/09/2015, 17:13

... distribution of propoxur and its transformation products in biota and soils, and additionally the difference in the 122 sample preparation processes (soils were spiked at ambient conditions and air-dried, ... extraction temperature and time 5.2.3.2 MAE procedures and the treatment of extracts For every sample in each species extracted by MAE, g of a spiked sample was accurately weighed out and quantitatively ... assignment of the main variables (A, B, C and D), two-variable interaction, and the level setting values of the main variables applied to aquatic animals (goldfish and tortoises) and sea lettuce...

Ngày tải lên: 16/09/2015, 17:13

... Influence of matrix, moisture, aging of spiked soil on recovery of tested pollutants The effects of matrix, moisture and aged spiked soil on recovery of analytes were investigated and the results ... following was performed: ml of standard solution containing ppm of propoxur, thiuram, propham, methiocarb and chlorpropham was evaporated to dryness and, then 30 ml of the appropriate extractant ... Experimental 4.1.2.1 Reagents and soil preparation Analytical-grade PAHs (naphthalene and phenanthrene), PCB (PCB-1242 and PCB1248), triazine (atrazine 98% and simazine 99%), and carbamates (propoxur...

Ngày tải lên: 16/09/2015, 17:13

... application of LC-APCI-MS for the determination of carbamates: carbofuran and 3hydroxy-carbofuran, and the analysis of triazine herbicides in water [8] LC-ESI-MS ... sets of standards of propoxur dissolved individually in methanol and ultrapure water were prepared with the concentrations of 0.025, 0.05, 0.10, 0.25, 0.50 and 1.0 ng/µl, respectively A set of ... concentrating propoxur and its TPs from the water samples because of the efficiency and simplicity of this extraction method A 100-ml sample was firstly adjusted to pH 3, and then transferred to...

Ngày tải lên: 16/09/2015, 17:13

... volume of spiking solutions into the natural water samples prepared above and ultrapure water All the samples were degassed by an ultrasonic bath before LC-MS analysis 2.3.2 Preparation of Soil Samples ... fortification standards for recovery and analytical precision, a portion of each fish sample was added an appropriate volume of standard solution, thereby obtaining the required levels of target analytes ... air-dried, pulverized and sieved through a 60mesh sieve In order to remove possible traces of PAHs, PCBs, triazines, carbamates and other organic contaminants, 100 g of each of the soil sample was immersed...

Ngày tải lên: 16/09/2015, 17:13

... LC-APCI-MS is often used in various stages of drug analysis, environmental analysis of pesticides and herbicides (in water, air, and soil), and metabolite studies 1.3 SAMPLE PREPARATION TECHNIQUES ... development of a complete analytical method includes sample storage, sample preparation, analyte separation, identification and quantitation Among these, sample preparation is the most tedious and time-consuming ... sensitive and selective analysis of triazine and phenylurea pesticides in environmental samples [118]; sample volumes of 20 ml of ground water provided LODs 26 Table 1-5 The application of LC-API-MS...

Ngày tải lên: 16/09/2015, 17:13

... flow profile in contrast with the parabolic flow profile of pressure driven flow and lead to better resolution Fig 1.1 Process of silanol dissociation EOF causes the same direction movement of entire ... conviction of guilty offenders and the appraisal of the consanguinity Amino acids, peptides and proteins Proteins are very important to life, the complex molecules of proteins are made of L- amino ... applicability of capillary electrophoresis (CE) in the analysis of natural products, which offer a vast and virtually unlimited source of new agents for both the pharmaceutical and agrochemical...

Ngày tải lên: 11/09/2015, 14:27

Ngày tải lên: 17/02/2014, 20:20

... One common cause of failure is the inability of the grammar to deal with all the nuances of adjective comparison: The total number of triples generated was 51,115 and the number of unique triples ... labor of enlarging a parser lexicon such as the LSP Dictionary And it is much faster This way of looking at our results may make it appear that parsing was a waste of time and effort, of value ... conjunctionphrases expanded, passives inverted, inflected forms analyzed, and other modifications of the kind often brought under the rubric of "transformations." The LSP can this sort of thing very...

Ngày tải lên: 08/03/2014, 18:20

... chimpanzee and human autosomal genome sequences chimpanzee lineage and that of the common ancestor of human and Neandertal before the split We use the Neandertal sequence in a three-way Neandertal-human-chimpanzee ... seen in human (Neandertal and chimpanzee being equal) and chimpanzee (human and Neandertal being equal) With the knowledge of the divergence time between human and chimpanzee and assuming no differences ... S: Optimization of 454 sequencing library preparation from small amounts of DNA permits sequence determination of both DNA strands Biotechniques 2009, 46:51-52 54-57 Rohland N, Hofreiter M: Ancient...

Ngày tải lên: 09/08/2014, 20:22

... ∞, and the solutions of (46) are global Zheng and Feng Journal of Inequalities and Applications 2011, 2011:20 http://www.journalofinequalitiesandapplications.com/content/2011/1/20 Page 14 of ... the set of real numbers as R, and R+ = [0, ∞) is a subset of R Dom(f) and Im(f) denote the definition domain and the image of f, respectively Theorem 2.1: Assume that x, a Î C(R+, R+) and a(t) ... Zheng and Feng Journal of Inequalities and Applications 2011, 2011:20 http://www.journalofinequalitiesandapplications.com/content/2011/1/20 Page 11 of 15 Then z(x0 , y) ≤ J−1 [v(x0 , y)], (41) and...

Ngày tải lên: 21/06/2014, 01:20

... Table of Contents Page i Acknowledgements ii Table of contents Part I: Introduction 1.Justification of the Study 2.Aims of the Study 3.Scope of the Study 4.Methods of the Study 5.Design of the ... declaration of independence And on September, 2, 1945, in Ba Dinh square, Hanoi, he read the declaration before thousands of people on behalf of the Provisional Government of the Democratic Republic of ... declarations of France and the United States of America On one hand, Uncle Ho praises political ideologies in these documents On the other hand, he condemns the national oppression and violation and trampling...

Ngày tải lên: 14/12/2013, 00:41

... Description of Data collection 2.5 Procedure 2.6 Preliminary results and data analysis 2.6.1 Results of section of test 2.6.2 Results of section of test 2.6.3 Results of section of test 2.6.4 Results of ... Errors and their causes 2.7.1 Errors and their causes in section of test 2.7.2 Errors and their causes in section of test 2.7.3 Errors and their causes in section of test 2.7.4 Errors and their ... abbreviations List of tables Table of contents Part 1: IntRoduction Rationale of the study Aims of the study Subjects of the study Scope of the study Method of the study Design of the study Part II: Content...

Ngày tải lên: 18/12/2013, 10:04

... about Theme and Rheme, although "The Analysis of Theme and Rheme in "Little House on the Prairie" is shown as the theme of the study Method of the Study - A great number of documents and materials ... linguists Though points of view of many linguists and scholars of different schools can be included in this thesis, of which, Halliday (1994) should be considered the main source and the basic reference ... out of the context Moreover, the common traditional practice of language teaching and learning has been on the analysis of single sentences, normally at the levels of phonology, vocabulary, and...

Ngày tải lên: 22/12/2013, 12:59

... (starch and soluble carbohydrates) during that time period of cold exposure Effect of cold exposure on levels of soluble carbohydrates and starch Contents of leaf starch, sucrose, hexoses and raffinose ... activities of enzymes in central carbohydrate metabolism during cold exposure (A–C) Vmax values of three invertase isoforms: vInv, nInv and eInv (D) Vmax of SPS (E, F) Vmax values of FrcK and GlcK ... content of the supernatant was then determined and used to assess the starch content of the sample Measurement of enzyme activities Enzyme activities were determined in crude extracts of leaf samples...

Ngày tải lên: 14/02/2014, 22:20

... the Ministry of Health, Labour, and Welfare of Japan announced the guideline value of formaldehyde first and individual volatile organic compounds (VOCs).13, 14) In Japan, occupants of newly built ... conducted to confirm and extend the U.S.A case definition of MCS The results showed a significant overlap of MCS, chronic fatigue syndrome (CFS) and fibromyalgie, and that no standard diagnostic procedure ... consideration of public health.38) The relationship between moisture and temperature on skin and upper airway symptoms was investigated and showed that skin dryness and rashes, pharyngeal dryness, and...

Ngày tải lên: 17/02/2014, 22:20

... variety of scenes, certain attributes of spatial configuration (such as the extent of openness and spatial definition, the normal function and/ or use of the place, and the age of the site and its ... Frequency of use of most attractive and most unattractive places 24 GALINDO AND HIDALGO Figure Average scores in the aesthetic attributes of the most attractive and unattractive places presence of ... 1997) two types of variable in the context of urban design: Attributes of formal aesthetics and attributes of symbolic aesthetics Among the former, the authors highlight ‘‘openness’’ (and/ or spaciousness),...

Ngày tải lên: 19/02/2014, 17:20

... Malaysia, Lao PDR, Myanmar and Cambodia Thailand has two long coastal lines, one along the Gulf of Thailand (1870 km) and one along the Andaman sea (800 km) Today, Thailand is one of the leading tourism ... use of nursery ponds This technique is called "staging" and facilitates the feeding and counting of the shrimp (Tobey et al., 1998) 18 6.5 Grow-out techniques The long coast line of Thailand and ... large number of unregistered inland shrimp farms in Thailand today An association of inland shrimp farmers reported that inland shrimp farms have a total pond area of about 22 400 and would be...

Ngày tải lên: 26/02/2014, 20:20